Rotary furnace or kiln



G. F. DOWNS.

A ROTARY FUHNACE OIR KILN.

v APPLICATION FILED JUNE I9, 1920.' 1,381,096. f

Patented June 7,' 1921*..

4 SHEETS-SHEET I l h /f/l /f/// ///l G. F. DOWNS.

:mmm ruRNAcEon KILN.

APPLICATION FILED JUNE I9, 1920.

Patented June 7, 1921.

4 SHEETS-.SHEET 2.

lG. F. Downs.

4ROTARY FuRNAcE 0R KILN. APPLICATION FILED .IIINE I9, |920.

ramen June 7', 1921,

4 SHEETS--SHEET 3.

'yangel-@w25 G. F. DOWNS. i ROTARYv FuRNAcE '0B KILN.

- 'APPLICATION JUNE 1.9, 1920. 1,381,096, Patented Jun@ 7, 1921.

` 4 SHEETS-SHEET 4.

GEORGE F. DOWNS, F BUFFALO, NEW YoRx'.

" c yROTARYjFURNAcE 0E Kinn. f

Application nieuwe 19, i920, 'serial Nb. 390,242.

Z' 0 all 11i/omit may conocia:

Be it known that I, GEORGE Downs, i a

" citizen ofthe United, States, and a resident of Buffalo, in the county ofErie and State of New Yorlq have invented certain'new and useful Improvements in- Rotary' Furnaces or Kilns; and I Ado hereby, declare that they follawingis a full, clear, andy exact de' script-ion thereof, reference being had to the f accompanying drawings, and to the letters of reference marked thereon, which formay part of this specification. a

This invention relates to improvements in rotary furnaces or kilns adapted' forroasting, sintering or like treatment of iue dust,

iron lore and other concentratesandconsists of the matters hereinafter` described and more particularly pointed out' 'infk the appended claims. c 'l i The improved furnace or'kiln'is of the genera-l type described in myiprior Patents No. 1,121,906 of December 22,1914, and Ito.

1,151,174 of Augustei, 1915.

The furnace iscylindrical and Y ward'the discharge end and the flue' dust or ore concentrates is subjectedin its passage through the rotating furnaceto heat, which Vis produced .in the beginning -by means-of fuel, either finely Vdivided carbon or gas blown` in at the discharge end of the furnace. In addition, thematerial is subjected'to heat producedby., the cenibustionof the finely divided carbon contained in it, so

that the. ore is thoroughly heatedp'd and caused to agglomerate into a sinter, in which form itis delivered from the discharge end ofthe furnace. g From this sinterft'he' metal is finally recovered inv another apparatus in a familiar manner.

In thc course of they passage of 'the i dust through the furnace, .it is Vsubjected to,

the action, of blasts ofair directed'through twyers Vwhich blasts not only provide'the'- air necessary for burning the carbony content of the fiue dust, but in addition, actto scatter and violently agitate the material being treated, thus producinga continuous bombardment Vof the material: inlits passage` through the twyer area, or blast chamber.

This facilitates the ffmef chemical union of the metallic or binder com of the furnace.

is Siighuy' inclined downwardly from the feed end 5tof- Referring now'to the Sepeccationof Letters APatent, y i Patented June?, 192]" tent. of they material, "while :the chemical Y proc-ess of combustion vprovidesthe -neces- 'W' sary heat to permit such mechanical union. The improved, vkiln is provided with a novel Aform and construction .of sintering or means for collecting the heat from thesin- .The improved furnace is provided Vwith .blast kchamber.designed to retard the travel of the niaterialbeing treated throughjthe i" kiliiain thel space orl location where the actual sintering operationptfakves place,

tered material as it is discharged from the l r furnace,"`which heat' ywould, otherwise y,be `wastecl, and for making use of said heatfto pre-heat the air supplied to the blast chamr E ber.

" It is sometimes l'found that the material lto 70 y be sintered does vnot carry enough fuel tok secure ythe proper amount of heatand to sup-y plement this heat, I have provided an auX- iliary fuel bin and'fuel pipe in the neighfuel directly 'into the sintering chamber.

borhciod of the discharge end of the furnace 'y lwhich is adapted to'discharge additional My invention also includes 'a novel con-iy i struction, connection and'inounting 'of the twyer and blast rings, whereby proper en*- .f'l

gagement y is `-maintained vby the r two rings,

while at the' same time `the Vblast ring is pei'- initted to' hfavcthe necessary' movement in the direction of the length of the furnace to accommodate the expansion fand contraction ofthe furnace.z i Y y I he improved `kiln or furnace has other novel features and advantages whichf'will be pointed out `more particularly as I proceed` with my specification. n y

drawings Figure 1 isaview of the discharge endo a l my improved rotary furnace, part in side elevation vand partt in longitudinal vertical rsection through the central axis ofthe furnace; l E a Fig. 2 isa view representing on an en-A larged scale, a transverse section ofthe blast i or twye'r chamber, the plane ofthe section being indicated by theline 2 2 of Fig. l.

Fig. 3 is a view: representingonV a like scale, a transverse sectionthrough the furnace in `the plane indicated by the line 3'-3 of 1.

7Fis ,t is e view representing a lol.igggitudby Fig. 7 is a radial section through the blast ring, twyer, ring and furnace wall., in a planemdicated by the line VZ-fl'of Fig. 3.

Fig. 8 1s a detail elevation of'part of the blast ringV showing the grease grooves for lubricating the twyer ring'.

F ig.v 91s a developed loaigitu'dinal sec- V i' tional' view lof the blast'box.

j Figi 10 is an enlarged, longitudinal, sectional view of the discharge end ofthe blast main.

i Referring' now to thatembcdiment of'iny invention illustrated in the drawings:-1O

indicates v the furnace proper which consists of aV rotating ycylinder linedv on the interior with refractory material and mounted to rotate on supports, one only of which, 11, namely the one near the discharge end of the furnace, isshown. The supports as usual are provided with antifriction rollers 12'.- The cylinder has annular bands or rails y 13 fixed Vto its outer. surface and bearing upon theantifriction rollers 12 and is aranged to bev rotatively driven ina familiar manner not shown. The discharge end of the furnace is closed by the familiar hood 14. l My improved furnace is provided with `means adapted to make use of the waste heat of the sintered material, for preheating the airV supplied by the blast main to theblast or twyer chamber. 16 indicates the masonry which provides the support for 'i the hood 14 and for the other apparatus located jat the discharge end of the furnace. vThe pocket 15 in the hood is continued down int-o said masonry by a passageway 17, vwhich leads to a conducting pipe 18, having a flaring discharge end 19, which is locatedin the top of an upwardly inclined, .rearwardly extending casing 20. Said casing provides a closed chamber in 1 which is located an inclined, endless conveyer 21. The conveyer is in the form of a belt made of suitable material' to resist the heat of the sintered material,whieh is discharged upon it bythe pipe 18. It

' extends at each end, through suitable openings in the end walls of the casing 20, outside of which it is mounted on pulleys 22-22 supportedv in convenient manner, the bottom lap being, supported by vtransverse rods or rollers 23 located within the casing; The rear, higher end of the casing 20, which may be called the heat collecting chamber, vis connected to a second casing 24,.providing a heating or radiating chams Vber in which are located a plurality of heating tubes 25 arranged in vertically spaced planes. Said casing is provided with an opening or outlet 26 at the top and with inlet. and outlet passages 27-28 located in line with the heating tubes 25.

By this arrangement7 the hot sintered material is discharged upon the conveyer belt 21 in the chamber 2O and in its passage on said belt through the said chamber, the heat of the sintered material is given up and collectedv and then passes into the second chamber 24 where it is taken up by the heating tubes 25. The chamber 24 is interposed in the blast pipe (the inlet and outlets 27-28 forming part of said blast pipe) between the usual blower (not shown) and the discharge end 29 of said blast pipe. The air of the blast, as it passes in and about and between the hot pipes 25, is-heated by radiation from said pipes and in this way, the heat from the sintered material, which otherwise would be wasted, is used to preliminarily Vheat the blast supplied to the twyer 0r blast chamber.

In order to retard the flow of thematerial being treated in the blast or twyer area, the furnace cylinder is enlarged at or near its discharge end, as indicated at 30. ln the embodiment of the invention illustrated, said enlargement is provided by means of a radial, outwardly extending shoulder 31 and by a conical Vwall 32 offset from the diameter of the main length of the furnace, with its greater Vdiameter at the shoulder 31- and its smaller dia-meter `at the discharge end of the furnace. i

The `twyer pipes, insteadof 'entering the furnace Wall radially, as in my prior patents, are in the present instance parallel to the longitudinal axis of the furnace and extend through openings in the radial wall, 31 of the twyer chamber. twyer pipes which are of the usual construction and are arranged in a circle as clearly shown in Figs. 2 and 3. Said pipes are scoured in a flat ring 34 which is arranged in a plane parallel to but spaced back of the radial shoulder 31 of the twyer chamber and open through the face of said ring remote from said wall. The twyer pipes are made in two parts connected together by union ittings 33a, so that the twyer ring may be disconnected when desired. V35 indicates a blast heat which is a second fla-t ring having air-tight bearing engagement against the twyer ringr 34 and provided in oneA part of its periphery with an arcuate, elongated box 36 which is made integral with said ring and provides the blast box. n

The twyer ring 34 is supported by a plurality of radiallyl extending brackets 3T,

symmetrically located about the body of the Vfurnace and attached to the outside surface thereof,-the ring 34 being connected to said 33 indicates theI bracketszby a boltrand` slot connection '38,

asillustrated `inF ig. 7,'so asto'- be capable f horizontal earf39l'located adjaeentto.I the inner periphery of` the twyer ring.24and i adjusting screws 40, taking through.-said ears, provide for the ,necessary radialL adjustment of the ring." f j? f :The blast ring 35;.is supported; on `the twyer ringV in a radial *direction by means.

of'. a* plurality of antifriction rollers' 4l mounted .on radially yextending lugsv 42, ex` tending from'the.,periphery kof the tlwyerl ring. -.'lheblastfring" is held inproperen'- gagementagainst the face bof the twyerring by means of a plurality otarms 43 providing. spindles fori'antifrictionjrollers 44, which engage the marginsl ofthev blast ring.4 The arms 43ia're bent atrightanglesjto'itheaxis of the rollersl and extendthroughfholesjin radial extensions 45 `of the `twyer ring,t`he necessary pressure being provided .inh each case,`by a" spring 46 whichis interposed `-betweenthe lugand a vnut'on the end lof the arm, as r`shown in Fig. 5. Eachk arm is heldl against rotation in its opening by'means of a key 43a. .The arms and rollers43`44 Vare arranged symmetrically about the rings, vin alternation'onathe inner and"y outer sidescf said rings, as shown infF-ig.y To provide the necessary lubrication between the rings,

inner surface nea-r itsr` inner and outer 'pe-g ripheries,-(see Figs. 5 and 8), said grooves having a plurality of `branches 48 leading toward the median line Aof theringfas shown in Fig. 8;l The lubricant for-said groovesl is supplied by suitable'grease cups 49 have" ing inlets thatextend through lthe blast ring and enter] into thef bottom of@k the grooves 47447.,A At one part of the blast 4ring is provided an elongatedslot 35a `(see Fig;.3)lv

which exposes two vor moretwyer openings in the ring 34,y so that the twyer pipesmay be cleaned, when in the rotation of the furnace, they come into4 the area of-saidfslot.l

In thefbox 36 providingfthe blast box,

are located a plurality of spring-controlled' valves 50,which are spaced apart ,distances equal to the distance betweenfthe tw'yer` pipes. Said valves areadapted tov close l'under the action of their springs against-the` openings in the twyerjringcommunicatingwith the twyer pipes andtheir lstems prof ject beyond the box, through suitable stuilng.E`

boxes, where theyare provided with handles 51 for withdrawing them 'against theaction oit their springs. .Hand'controlled triggers '52 are associated with the several valve stems tor locking them in open position? (see Fig# 6), By :manipulation of theselva'flves` the number of twyerlpipes tol receive the blast may be controlled and adjusted to suit 0 f` l 'f down to sult all required conditions..r

ditions'.rvr

y f In orderto hold the blastspring 35fa'gainst rotative 'movement with the furnace and twyer ring, it is provided (as shownrrin thezneighborhood of the blast box) with ay radial, depending anchor `block 53, which engages in a channel 54 of a'barfl'lL-the channel extending parallel to the length of the furnace.v` r.Said bar is'rig'idly mounted in any suitable manner, as lfor example, onV

ment, but .at 'the` same time is'V permitted tol movein a longitudinal directionasthe kiln expands-for contracts, also-toi :follow vany eccentric rotary `movement of -the 'kiln'.

,. lThe blast pipe-29l near the kilnissupport-i` sov ed and rigidly held'by thefbeams 58. Ailexible-section .29.al connects thisv xed Lpart of the blast pipewith thek blast chamber (see Figlwl) theflexibility of this. inlet partof the pipe accommodating the movement of the blast ringyin the'xexpansion. oracontrac-A ytiono' the kiln (see Figslqlfand 1());v`

60 ,indicates the usual. fuel .bin ,and 611 and 62theusual blower ,and fuel pipeconA- "nected thereto, all-beingsu'pported on the masonry 16 at 'the -discharge end of the fur*- na'ce; In "addition, therel is-fprovided an-v auxiliary fuel'bin 63, andl a fuel discharge pipe 164f-conn`ected therewith.k .Thea'latter extends through vthe hood and Fis arranged.

to discharge fuel by gravity-.directly upon.

v the material being treated, as shown in Fig.v`

fuel to supply the required amount of heat.` n The discharge opening ofthefurnacemay l.y This auxiliary bin `and fuel pipey are.

rbevvaried to suitconditionsbyf means of av nose ring 65, which is supported onthe discharge end ofthe kiln by a suitableflange 67. The discharge opening 67lmay be varied by using noserings havingopenings of dif-i kferentdiameters.' e

.lt will be` manifest that on account of the enlargement of the kiln in the twyer area,

the movementof the material being treated through the twyer area will be slowed down, thus giving more time to the sintering proc-* ess. *This slowing-down is further-increased by the converging 4shape of. the" wall of the furnace-tovvardthe discharge opening which. T makes it necessary for the material lin the e bottom of the furnaceftoclimb up an inf clineon'itsfway to the discharge opening.

The slowing'down may manifestly ,bey stilll further 'effected by diminishing the diameter.

of the opening in the nosering.f f Thus l)the time during kwhich the sintering process is carried on 1n thetwyer area,`.mav be slowed fWhile-in describing my invention, I have l referred to certainU details: of mechanical constructionk and `arrangement of parts,`I do not Wish totbelimited thereto exceptas may be pointedout in the appended claims.

Iclaim as my invention:

l. In a furnace of the kind described, a rotating cylinder, said: cylinder being enlarged in the twyer area to provide a sintering chamber of diameter greater than the diameter of the restof the furnace chamber.

' 2; :In a furnace of the kind described, a rotating cylinder, said cylinder providing lsoV therethrough.`

' 5. In a furnace" of the kind described, Aa`

4. In a furnace of rotatin l ward-t edischargeu end, a radial'wall part extending outwardly from the main body of the cylinder, and an annular wall part connected thereto, -converging toward 'the dischange' endof the cylinder, saidtwo wall parts provi-ding an enlarged 's intering. cham-` er adaptedl to` retard the flow' ofV material rotatingcylind'er yhaving a discharge tend, saidcylinder having anV outwardly extending,lradial wall part and a wallpart which is tapered inwardly .froml said radial wall part toward the discharge opening and means forV varying the 'diameter' ofthe discharge opening.'V

6. Ina furnace of the kind described, a

rotating cylinder having adischarge end,

said cylinder having an outwardly extend# ing, radial wall part and a wall part which is tapered inwardly from `said' radial'wall part toward the `discharge opening, land a nose ring at said discharge end for determining the diameterV of the discharge opening. Y Y

7. In a furnace of the? kind described, aY rotating cylinder, means providing a sinter- `ing chamber at the dischargel end of the cylinder, said chamber beingof a diameter at one end 'greater than that of the cylinder and *beingl of substantially'the diameter of' the cylinder at its outer end which providesV -the discharge opening.

8. In a furnace of the ln'nd described, a rotating cylinder, means providing a sintering chamberv at Aor'near the discharge 'end of the cylinder-and means for discharging air into said sintering chamber in aA direction parallel with the longitudinal axis of the cylinder.. r f

cylinder,- saidk cylinder having, to#

9. In afurnace .of the kind described, Ia rotating cylinder, means providing av sintering chamber at or near.` the discharge end of the cylinder, and means for discharging air into said sinteringchamber inthe: direction of the travel of thematerial through the furnace.` y v 10. In a furnace'of the kind described,.a rotating cylinder having a sintering chamber of greater; diameter than that of the mainbody `of Vthe cylinder, said sintering chamber having a Wall part extending radi-A ally outwardl from the cylinder body, Va twyer ring spaced from said radial part Vand rotating with said cylinder, a plurality of twyer'pipesconnected to saidring and. ex-y tending through said wallv partjand anon-A rotative blast .ring engaged .with saidl twyer: ring, said. blast ring having' an elongated blast boxk which is adaptedfto communicate withfthe twyer pipes in succession as the cylinder is rotated.;

11. In a furnace of the kind described, a' rotating cylinder having a sintering cham ber of greater diameter than that-.of the main body of vthe cylinder, saidfsintering chamber having a wall part extendingradially outward'from the cylinder body, a twyer ringspaced'from said-radial part and rotat ing with the cylinder, aplurality offtwyer pipes connectedto'said ring and extending through. said wall part, anda non-rotative blast ring engagedY with said twyer ring, said blast ringhaving an elongated blast box adapted toA cover a plurality of'twyer pipe openings in the blastring Y 12. In a furnace of the kind described, a rotating cylinder having a sintering chamber of greater diameter than that of the main body of the cylinder, said sintering chamber having a wall part extending radially outward from the cylinder body, a twyerv ring in a plane parallel to said wall part and spaced longitudinally'therefrom,

twyer pipes lconnected* to said twyer'ring and extending through said wall part, a blast ring engaged with said twyer ring, and means for holding said blast ring against rotation of the cylinder whilepermitting a movement thereof' longitudinally of the cylinder.- Y

. 13.l In a furnace of the kind described, in combination with a rotating cylinder, a twyer ring surrounding thel cylinder and located in avplane at right angles vto the axis of thel cylinder, a non-rotative blast ring engaged with said twyer ring and having an elongated blastvbox, a blast conduithaving a flexible 'inlet connected to said blast box, and means for holding said blast ring against rotation but permitting a movement thereof longitudinally of the cylinder.

14. In a furnace of the kind described, in combination with a rotating cylinder, a twyer ring surrounding said cylinder and rotatable therewith, saidtwyer ring being in aplane at gright anglestothe axis aof.

said cylinder, a blast'ring rotatively engaged with said twyer ring' and having' an elongated blast box, an anchor on saidfblastL ring, means engagingsaid anchor adapted to lock the same against rotativemovement but permitting movement inthe'fdire'ctiOn of the length of the cylinder, a blastcnl.

duit, and a flexible blast inlet .connectingv said conduitwith'aid blast SboX.-`

` 15. In a furnace of the kind'described, in combination with a rotating cylinder, al twyer ring' surrounding said` cylinder and rotatable therewith, said twyer ring being ina plane at right anglesto the axis ofrsaid cylinder, a non-rotativeblast ring engaged with said twyer ring andhavin'g ablastbox,

an air conduit having afleX-ible inlet K fcon#` nected to said blast box, an anchor dependv 17. In a furnace of the kind described, ad

rotating cylinder having a radial wall part, a twyer ring parallel to and spaced longitudinally from said wall part, twyer pipes connected to said ring and extending through said radial wall part, radial supporting brackets on said cylinder for said"` twyer ring, and adjustable bolt and slotcon nection between said ring and the brackets, and radially extending set-screws carried by said brackets and engaging saidtwyer ring adapted to provide a radial adjustment" of said ring with reference to said cylinder.

18. In a furnace of the kind described, la rotating cylinder, a twyer ring surrounding and spaced from said cylinder,`means' ony said cylinder for supporting said ring, a non-rotative blast ring engaged with said twyer ring, antifriction roller supports carried by said twyer ring and engaging the periphery of said blast ring,vand antifriction spring compression devices engaging the face of said blast ring and holding it in engagement with the twyer ringl 19. In a furnace of the kind described, a rotating cylinder, a twyer ring spaced radially from said cylinder, means on said cylinder for supporting said ring, anonrotative blast ring engaged with said twyer ring, supporting rollers carried by said twyer ring and engaging the periphery of said blast ring, non-rotative, longitudinally 20, Inaffurnaceof the kind `the grease grooves.

andfrollers on saidistuds engaging the outer gagement'with the twyer ring. v

y described, a rotating cylinder,-aftwyer ring rotative with vsaid cylinder, twyer pipes connected to"'said`ring,-a non-rotative blast ring .engagedwith said twyery ring, said blast ring havingfan'-elongated, arcuate vblast box, adapted to' include a pluralityof twyer pipe openings vin said twyer ring, and a'plurality of valves in said box spaced at distances corresponding toithefspacing of-said twyer pipe' openings, saidl valvesy having stems projectlngoutsideof said blast box.y

1421.I Ina furnace ofthe kind'described, a rotating cylinder, a twyer ring rotative with said cylinder, twyer pipes connected to said ring, al lnfnifrotative yblast ring engaged Vwith face of said'blastring and holding it in'end said twyerring, "said lblast ring having an f elongatedfarcuate blast boxfadapted to includefajplurality of twyer'pipe openings in said twy'erV ringya plurality of spring controlled valves in saidboxsp'aced atdistances corresponding' to the spacing of said twyer `pipe `openings",fan`d' devices for locking said valves in open'"position,l f"

22,. In a furnaceof the rotating cylinder, a twyer', ring rotative with thefurnacdQtwyer Lpipes connected to the twyer ring, a4 non-rotative blast ringV engaged with the-twy'er: ring, said blast' ring having kind described, a

a blast kbox whichcommunicates with a plurality kof twyer pipes in said twyer ring, said blast ring having an arcuate slot, spaced from theblast box to exposethe pipe openings in said `twyer ringfor rcleaning purposes. e r

23. In a furnace of the kind described, a vrotating cylinder, a twyer ring rotative with the cylinder, anon-rotative blast ring having flatr 'face engagement with the blast ring, said inner and outer p'eripheries, each having a plurality of branches extending toward the middle artv of said ring, and grease cups carried y the blast ring and opening into 24. In a.k furnaceofrthe kind described, in. combination with the rotating cylinder having a ysintering chamber at one end and means for blowing fuel intoy said chamber in a direction parallelto the longitudinal axis of the furnace, an auxiliary fuel supply hopper, and a discharge pipe leading from' the bottom .thereof for directing fuel under in combination. with a'rotating cylinder, the.

blast head associated therewith and the blast conduit connected to said blast head, a con- Vconveyer` belt at *the discharge `end of the furnace for receiving thematerial discharged therefrom, a casing providing va heating chamber aboutsaid conveyer belt, and means for providing a radiating chamber connected to said heatingfchamber at a point remote from the receiving end of said conveyer, said radiatino chamber .being interposed in the length of said fblast conduit. Y Y

f 26. In a furnace of the kind described, in combination Withv a rotatinggcylinder, the blast head associated therewith landthe blast conduit connected Ato said-blast head, means for receiving and conveying away the vmaterial discharged Yfrom the* saidV furnace, a casing providing` a radiating chamber inter posed in said blast conduit, andflneanszfor collectingy the heat radiated from .ther-discharged material and kconducting vit to said radiating chamber. Y 27. In a. furnace of the kind described, in. combination With a rotating cylinder,the blast head associated therewithandthe blast conduit connected to said ,blastfheadfmeans for conducting the lfuel from gthe idischarge end ofV said furnace to: a point'remote-from said discharge end, and means connected with said blast conduit .for collectingtheheat of the discharged fuel and supplyingit to .said blast conduit to pre-heatthe blast of airpassing therethrough. y I n y 28. In a furnace of Lthe kind described, in combination Witharotating cylinder, a tWyer ring, `surroundin the -cylinder and located a plane at rig tangles totheaxis ofthe cylinder, ai non-rotative blast .ring engaged With said tWyer ring and having an elongated :blast'box, a blast conduithaving ajflexible inlet connected to said blast box, and means for holding said blast ring against rotation but permitting agmovement of said blast ring ina direction longitudinal of the cylinder and in a direction transverse of said cylinder. Y

V29. In. a furnace .of the-v kind described, in combination with a rotatingicylinder, a tvvyery ring surrounding saidcylinderl and rotative therewith, VsaidtWyer ring being in aplane vat right `angles toytheaxis of said cylinder, a blast ring rotatively engaged y with said tW-yer ring and having an elongat-y ed blast box, an anchor on. said blastring, means engaging saidfanchor adapted to lock the same against rotative-movementbut.permitting movement in the direction of ;the length ofthe cylinder and yin a,plane at right angles thereto, a blast conduit,and a flexible blast inlet connecting saidaconduit@With said blast box. Y

In testimony lthat -I -claimthe foregoing asV my invention, I affixl my signature in the presence of two Witnesses, this 16thl ,day of JuneLD. :1920.

d GEORGE F. Downs. Y Witnesses: Y l I J. WUNsoH, E. F. JULIUs. Y 

